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Hello,

I am trying to simulate embankment overtopping with Telemac3D. I have problem with flow simulation. As you can see from the attached image, the flow downstream of the embankment from toe to some distance upstream is very noisy; however, expected to be smooth as same of the crest. Any idea?

Hello,

This is very strange, and interesting as it does not totally seem to be a numerical effect (you have some sort of such waves generated when rain flows over a slope). I would however try with a more realistic horizontal diffusion. See e.g. if it changes something with diffusion equal to U*DX/2 (to see a numerical effect). Friction also must have an important effect, though Strickler 104 is nearly like glass.

With best regards,

Jean-Michel Hervouet

Hello,

This is a flume test. My mesh size is 0.01m by 0.01m triangular. I assume U is around 2m/sec downstream slope. so U*DX/2=2*0.01/2=0.01.
The surface is fine sand with 0.295mm size and I calculated and found that strickler coefficient is 104.

Best Regards,